The conditions in which motor graders are used requires that the entire suspension for the grader blade be extremely rugged and able to withstand severe stresses encountered in use. It is desirable that the rugged construction and stress resistance be achieved, however, by sound structural engineering, rather than by sheer massiveness of components, both to reduce material costs and to reduce power requirements in operation of the grader.
In addition to the need for increasing strength and ruggedness of equipment without substantial weight increase, or even with some weight reduction, manufacturing costs can be controlled by reducing the number of components required to achieve the same result; and also by avoiding constructions which require building to close tolerances.
Another important factor in any type of industrial equipment, and particularly in very heavy equipment which must often be field serviced, is the ease of servicing which includes, of course, the removal and replacement of worn parts.
Patents which disclose typical prior art structures for supporting a grader blade on a motor grader circle include Leliter U.S. Pat. No. 2,799,099; Beyers et al U.S. Pat. No. 3,191,324; Fisher U.S. Pat. No. 3,463,243; and Fisher et al U.S. Pat. No. 3,465,829.